Do you get much exercise? For myself (I am 48) I know that if I do not exercise, I feel tired and low energy, and when I do go to sleep my mind is often engaged with some issue of the day. Aerobic exercise helps, such as jogging, playing soccer, softball, TKD or the like, but I find that weight lifting (heavy weights, as much as I can lift, not light weights with high repetitions) helps me the most in getting exhausted to the point that I fall to sleep quickly. I need both aerobic and weight exercise, plus stretching to keep in good shape, feel energized and get a good night's sleep. IMO nothing calms the mind better.